- Total Synthesis of 7-epi-Pukalide and 7-Acetylsinumaximol B
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Convergent total syntheses of the furanocembranoids 7-epi-pukalide and 7-acetylsinumaximol B have been achieved using a one-pot Knoevenagel condensation and thioether-mediated furan-forming reaction. Furan formation proceeds via a sulfur ylide and results
- McAulay, Kirsten,Clark, J. Stephen
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- Selective Catalytic Synthesis of 1,2- and 8,9-Cyclic Limonene Carbonates as Versatile Building Blocks for Novel Hydroxyurethanes
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The selective catalytic synthesis of limonene-derived monofunctional cyclic carbonates and their subsequent functionalisation via thiol–ene addition and amine ring-opening is reported. A phosphotungstate polyoxometalate catalyst used for limonene epoxidation in the 1,2-position is shown to also be active in cyclic carbonate synthesis, allowing a two-step, one-pot synthesis without intermittent epoxide isolation. When used in conjunction with a classical halide catalyst, the polyoxometalate increased the rate of carbonation in a synergistic double-activation of both substrates. The cis isomer is shown to be responsible for incomplete conversion and by-product formation in commercial mixtures of 1,2-limomene oxide. Carbonation of 8,9-limonene epoxide furnished the 8,9-limonene carbonate for the first time. Both cyclic carbonates underwent thiol–ene addition reactions to yield linked di-monocarbonates, which can be used in linear non-isocyanate polyurethanes synthesis, as shown by their facile ring-opening with N-hexylamine. Thus, the selective catalytic route to monofunctional limonene carbonates gives straightforward access to monomers for novel bio-based polymers.
- Maltby, Katarzyna A.,Hutchby, Marc,Plucinski, Pawel,Davidson, Matthew G.,Hintermair, Ulrich
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supporting information
p. 7405 - 7415
(2020/05/25)
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- Bimetallic Radical Redox-Relay Catalysis for the Isomerization of Epoxides to Allylic Alcohols
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Organic radicals are generally short-lived intermediates with exceptionally high reactivity. Strategically, achieving synthetically useful transformations mediated by organic radicals requires both efficient initiation and selective termination events. Here, we report a new catalytic strategy, namely, bimetallic radical redox-relay, in the regio- and stereoselective rearrangement of epoxides to allylic alcohols. This approach exploits the rich redox chemistry of Ti and Co complexes and merges reductive epoxide ring opening (initiation) with hydrogen atom transfer (termination). Critically, upon effecting key bond-forming and -breaking events, Ti and Co catalysts undergo proton transfer/electron transfer with one another to achieve turnover, thus constituting a truly synergistic dual catalytic system.
- Ye, Ke-Yin,Mccallum, Terry,Lin, Song
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supporting information
(2019/06/24)
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- Progress toward the Enantioselective Synthesis of Curcusones A-D via a Divinylcyclopropane Rearrangement Strategy
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We report our iterative efforts toward the divergent total syntheses of curcusones A-D via Suzuki coupling, intramolecular cyclopropanation, and a key divinylcyclopropane rearrangement. Progress of our synthesis was repeatedly challenged by the highly sub
- Wright, Austin C.,Lee, Chung Whan,Stoltz, Brian M.
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supporting information
p. 9658 - 9662
(2019/12/02)
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- OXIDATION OF LIMONENE
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The invention discloses a process for the oxidation of limonene, comprising the reaction of limonene with hydrogen peroxide in the presence of a catalyst containing atoms and/or ions of at least one metal, selected from the group consisting of molybdenum, tungsten, scandium, vanadium, titanium, lanthanum, zirconium, praseodymium, neodymium, samarium, europium, terbium, dysprosium, erbium or ytterbium, characterised in that the molecular weight of the catalyst is less than 2,000 g/mol and that the reaction is performed at a pH value of more than 7.5.
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Paragraph 0043; 0045; 0046
(2018/06/15)
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- Synthesis of (+)-perillyl alcohol from (+)-limonene
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(+)-Perillyl alcohol (1) has been synthesised in four steps and 39% overall yield from commercially available limonene oxide (4). The sequence features, as its key step, a palladium(0)-mediated transformation of a secondary allylic acetate (6) into its primary isomer (7). An application of (+)-perillyl alcohol (1) in a formal synthesis of naturally occurring (-)-mesembrine (2) and (-)-mesembranol was demonstrated.
- Geoghegan, Kimberly,Evans, Paul
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p. 1431 - 1433
(2014/03/21)
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- Total synthesis of (+)-cymbodiacetal: A re-evaluation of the biomimetic route
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A total synthesis of (+)-cymbodiacetal (1) has been completed from (R)-(+)-limonene oxide using a hetero-Diels-Alder cycloaddition as a key step. The key Diels-Alder cycloaddition proceeds with endo-selectivity (2:1, endo/exo) in quantitative yield, and t
- Uroos, Maliha,Lewis, William,Blake, Alexander J.,Hayes, Christopher J.
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experimental part
p. 8465 - 8470
(2011/04/15)
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- Biogenetic-Type Synthesis of (+)-Cymbodiacetal, a Constituent of Cymbopogon martinii
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A biogenetic-type synthesis of (+)-cymbodiacetal (1), a novel bismonoterpenoid dihemiacetal, is described.
- D'Souza, Asha M.,Paknikar, Shashikumar K.,Dev, Vasu,Beauchamp, Philip S.,Kamat, Shrivallabh P.
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p. 700 - 702
(2008/04/18)
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- A CONVENIENT SYNTHESIS OF (R)-(+)-PERILLALDEHYDE
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A short and efficient synthesis of the commercially unavailable (R)-(+) isomer of perillaldehyde from (+)-limonene oxide has been developed.
- Tius, Marcus A.,Kerr, Michael A.
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p. 1905 - 1912
(2007/10/02)
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